The present invention relates to a magnetic disk drive having a magnetic disk isolated from a driving section such as the voice coil motor which drives a head arm.
The magnetic disk used as a recording medium in a magnetic disk drive has a plurality of concentrically formed tracks, each of which is divided into a plurality of sectors. Sector address information and user data are stored into each sector. A head can write data into or read it out from desired sectors by accessing the sectors in accordance with address information thereof. The signals that the head has read out from the magnetic disk during data reading are subjected to waveform shaping, decoding, and other required signal processing, by the signal-processing circuit provided on the circuit board of the magnetic disk drive, and then transmitted to a host. As with the above signals, data that has been transferred from the host is subjected to required processing and then written onto the magnetic disk.
The above-mentioned head is fixed to a slider and installed at the front end of a head arm via a suspension. The driving force of a voice coil motor (VCM) operates the head arm, thus moving the head.
Such a magnetic disk drive has the problem in that the dust stemming from the internal VCM of the driving mechanism for the head arm, and from components such as the bearing used to fix the head arm, reduces the cleanliness of the enclosure interior of the magnetic disk drive.
Accordingly, there is known a technique for preventing the flow of dust from the VCM into the disk compartment containing the magnetic disk, by isolating the VCM from the disk compartment. Patent Reference 1 (Japanese Patent Laid-Open No. 7-320478), for example, discloses a construction that isolates a magnetic disk from a VCM via the upstream isolation wall and downstream isolation wall provided along the outer circumference of the magnetic disk, and via the pivot shaft of a head arm.
FIG. 6 is a plan view of the magnetic disk drive 50 disclosed in Patent Reference 1, with a top cover removed. A slider 501 is installed at the front end of a head arm 502, which is supported by an arm pivot shaft 503. The driving force of VCM 504 pivotally moves the head arm 502 about the arm pivot shaft 503. As shown, the VCM 504 and magnetic disk 505 are isolated from each other by the upstream isolation wall 507 and downstream isolation wall 508 that an enclosure 506 has, and by the arm pivot shaft 503. This construction prevents the dust stemming from the VCM 504, from entering the disk compartment in which the magnetic disk 505 is installed.